1. Field of the Invention
The invention pertains to a dual pneumatic tire inflator for simultaneously inflating two dual tires and thereafter equalizing the pressure in each of the dual tires through an equalizer valve to provide a quick and easy means for making certain dual tires are properly inflated and the dual tires are at the same pressure prior to returning the tires to service. More particularly the invention pertains to a dual tire inflator having a housing including an air pressure inlet, a gauge, a pair of dual tire inflation hoses having locking chuck valves for engaging and locking on each of the valve stems of the inside and outside dual tires and a pressure relief valve for equalizing the pressure between the pneumatic dual tires.
The novel dual tire inflator is designed for the attachment of the locking chuck valves to each of the tire or tube valve stems of the inside and outside dual tires to allow the equalization of pressure between the inside and outside of dual tires prior to the attachment of the air pressure source to the inlet flow valve which in combination with the gauge allows the equalization and provides a pressure reading for both of the dual tires of the dual tire arrangement. In this manner the integrity of each tire can be assessed as well as determining whether a leak or faulty valve condition exists in either or both of the dual tires prior to the attachment of the air pressure source to the housing.
The attachment of the pressure source to the inlet flow valve allows both of the dual tires to be simultaneously inflated to the same pressure so that subsequent removal of the air pressure source from the air inlet flow valve in the housing allows both of the tires to be simultaneously deflated to a predetermined and desired inflation through the utilization of the common bleed valve. In this manner both of the inside and outside dual tires for vehicles such as trucks, airplanes, tractors and trailers may be equalized to the proper inflation level thereby increasing the service life, efficiency and dependability of dual tire applications.
2. Description of the Prior Art
The importance of properly inflating and maintaining the pressure of tires has been recognized in the prior art in relation to the efficiency of the dual tire arrangement and the service life provided by each of the dual tires. As a result a number of different devices have been provided to carefully regulate and calibrate the amount of air admitted to pneumatic tires such as is represented by McAnally, et al U.S. Pat. No. 4,872,492. Such prior art devices have carefully controlled the amount of pressure provided to individual pneumatic tires but present difficulty in providing precise equalization of tires in dual tire applications due to the inaccessibility and difficulty in securing the pneumatic tire inflator to the inside dual of the dual tire arrangement.
In dual tire applications the prior art has provided a number of valve extension devices for attachment to the inside dual tire valve to make the inside dual tire more accessible to the tire pressure source. Such valve extension devices as are available from Schrader as Easy-Reach and Air Masters as Dual-Tire Inflators merely extend the length of the inside dual tire valve assembly to an accessible location on the outside dual. Such extension devices significantly increase the ease of equalizing the pressure between the inside dual and the outside dual tires by making the valve stems more accessible but they do not provide a means for simultaneously filling and equalizing the pressure in both the dual tires.
The most pertinent patented prior art appears to be Da Silva U.S. Pat. No. 4,875,509 which provides a device suitable for simultaneously filling and equalizing the pressure in both dual tires. In Da Silva U.S. Pat. No. 4,875,509 an air pump pressure control system is provided in which pressure may be simultaneously added to both dual tires through a pair of conduits connected through a valve means to a common pressure source to inflate both dual tires and to evacuate air from the tires in a deflating mode to equalize the tire pressure in the dual tires which is displayed in separate visual gauges. This device while assisting in the equalization of pressure in dual tires suffers the great disadvantage of not being portable. Therefore if the service center is not equipped with this device the operator must again individually inflate each of the tires and utilize a pressure gauge to approximate the pressure between the two dual tires. As a result such non transportable devices are not only an expensive means for equalizing pressure in dual tires but are only fortuitously available so that operators of vehicles having dual tires must generally rely upon the commonly available single tire pressure inflators to inflate both tires of the dual tire arrangement.
The most relevant portable device uncovered in the course of reviewing available products on the market was the Quick Way Tire Inflation System manufactured by Quick Way Inc. of Las Vegas, Nev. The Quick Way Tire Inflation System is an apparent outgrowth of the extension valve prior art of Schrader and Air Masters as previously discussed. In the Quick Way Tire Inflation System a pair of hoses are provided having fittings for connection to valve extension hoses for both the inside and outside valve stems of the dual tire arrangement. The Quick Way Tire Inflation System extension hoses for the inside and outside dual tire valve fittings are permanently mounted to a support at the hub to provide a quick connect to a housing having one quick fitting, a hose connected to another quick connect fitting, an inflow valve and a pressure gauge. The housing quick connect fitting is designed to connect to one of the valve extension hoses and the other quick connect fitting on the hose is designed to connect to the other valve extension hose. The inflow valve is designed for connection to a single air pressure source to simultaneously inflate both dual tires to the same pressure in both the dual tires.
The Quick Way Tire Inflation System does not include a bleed valve to deflate both tires to a simultaneous equal pressure and does not include a pair of hoses with tire valve locking chucks for engaging each of the tire or tube valve stems. Since the valve extenders remain permanently affixed to the inside and outside dual tires to keep the tire valve stems constantly open there remains a possibility for leakage at the open valve stem connection on the extender.
The Quick Way Tire Inflation System further does not include a bleed valve for equalizing the pressures between the dual tires and therefore does not equalize the pressures between the two tires to a predetermined level by providing an inflating mode to inflate the tires and to simultaneously and equally remove air from both the tires in a deflating mode. The Quick Way Tire Inflation System further requires the mounting of the valve extenders to both the inside dual tires and outside dual tires which can interfere with the operation and standard interchangeability of the tires from front wheel and rear wheel rotation and dual arrangement which generally requires the removal of the extenders from the inside and the outside dual tires.
The dual tire inflator of the invention in contrast provides a system which does not interfere with tire operation, rotation or the inside or outside dual arrangement and which does not require the addition of separate extenders or result in the system becoming useless when one of the extenders having a special fitting is lost or becomes damaged. In addition the dual pneumatic tire inflator of the invention allows the standard and commonly employed dual tire configuration in heavy trucks, aircraft and other installations to be employed without the addition or maintenance of valve extension apparatus which can become entangled in the dual tire gear or retraction mechanisms and thereby result in dangerous conditions as for example when the extenders become entangled in retractable wheel systems such as are utilized in commercial aircraft.
The novel dual tire pressure inflator of the invention is fully compatible with the standard dual tire arrangements without modification by employing a detachable valve chuck for locking onto the tire or tube valve stem when in use and providing for its removal when not in use from the valve stem to leave the tire in its unencumbered configuration after the equalization of pressure in the dual tires. The dual tire pressure inflator of the invention further allows the equalization of pressure in inflation and deflation to assure the more uniform equalization of pressure in dual tire arrangements.